1. Technical Field
The disclosure generally relates to heat transfer apparatuses typically used in electronic devices, and particularly to a plate type heat pipe with high heat transfer performance.
2. Description of Related Art
Heat pipes have excellent heat transfer performance and are therefore effective means for transfer or dissipation of heat from heat sources. Currently, heat pipes are widely used for removing heat from heat-generating components such as central processing units (CPUs) of computers. A heat pipe is usually a vacuum casing containing therein a working medium, which is employed to carry, under phase transitions between liquid state and vapor state, thermal energy from one section of the heat pipe (typically referring to as the “evaporator section”) to another section thereof (typically referring to as the “condenser section”). Preferably, a wick structure is provided inside the heat pipe, lining an inner wall of the casing, for drawing the working medium back to the evaporator section after it is condensed at the condenser section. A screen mesh inserted into the casing and held against the inner wall thereof is usually used as the wick structure of the heat pipe.
In operation, the evaporator section of the heat pipe is maintained in thermal contact with a heat-generating component. The working medium contained in the evaporator section absorbs heat generated by the heat-generating component and then turns into vapor. Due to the difference in vapor pressure between the two sections of the heat pipe, the generated vapor moves and thus carries the heat towards the condenser section where the vapor is condensed into condensate after releasing the heat into the ambient environment via, for example, fins thermally contacting the condenser section. Due to the difference in capillary pressure which develops in the wick structure between the two sections, the condensate is then brought back by the wick structure to the evaporator section where it is again available for evaporation.
Typically, the screen mesh is attached to the whole inner wall of the casing from the evaporator section to the condenser section. As a result, a space in the heat pipe for the vaporized working medium to flow through may be inadequate. This leads to a high flow resistance for the working medium, and thereby retards the heat transfer capability of the heat pipe.
Therefore, it is desirable to provide a heat pipe with improved heat transfer capability.